Genetic Improvement in Peanut: Role of Genetic Engineering

Peanut is a major oilseed crop, and a good source of protein, vitamins, and dietary fiber. It is widely grown in tropical and subtropical countries with varying levels of crop yields owing to biotic and abiotic stresses. Peanut improvement programs historically focused on improving yield, oil content, fatty acid content, moisture deficit stress, salinity, and disease resistance. Research efforts are now being targeted toward the enhancement of oleic acid, protein content, vitamins, essential minerals, dietary fibers, resveratrol, seed size and blanchability, and minimize the aflatoxin contamination and phytic acid and allergen production. Because of the complications associated with the ploidy level and compactness of peanut genome, stable gene transformation has been difficult. Despite the availability of peanut genome, studies on functional genomics associated with different traits are still at a nascent stage. The other concerns include the lack of optimized genetic transformation protocols and policy regulations on transgenic approaches. Multiple crop improvement techniques such as conventional breeding (cross, mutagenesis, and protoplast fusion); genetic transformation (trans-/intra-/cisgenesis); and genome editing (homologous recombination, zinc finger nucleases, transcription activator-like effector nucleases, and the CRISPR/CAS9 system) are being used/explored for peanut. In this chapter, a detailed description is provided of the various techniques that are currently deployed and future prospects for sustainable nutritional enhancement in peanut.